The output transistors can be BC548 and BC558. The circuit is from a 1975 documentation showing a frequency response from 90 Hz to 12.5 kHz.
This 90's Electronic Design circuit converts the period of a signal into a frequency. The...
These reset circuits when the power is turned on were found in an 80's EDN. The circuit also...
The receiver shown above was sent in by contributing reader Adriano Muniz Moura and is used for...